Granted Patent B2

US 8,982,362 · App. 13/645,000 · Granted Mar 17, 2015

Abstract

Claims (34)

1. A material deposition system for depositing a semiconductor material on a photovoltaic module substrate, comprising:

a deposition apparatus for depositing a semiconductor material on a photovoltaic module substrate using atomic layer deposition comprising a plurality of deposition cycles; and

a colorimeter comprising:

an optical source configured to illuminate, with optical radiation, a portion of the deposited semiconductor material;

a sensor configured to collect and measure color information related to radiation from the deposited semiconductor material; and

a processor coupled to the sensor and configured to receive the color information from the sensor and to use the received color information to calculate a thickness of the deposited semiconductor material, wherein the thickness of the deposited semiconductor material is calculated after every N deposition cycles executed during deposition of the semiconductor material, where N is a predetermined number.

2. The system of claim 1 , wherein the semiconductor material is selected from the group consisting of ZnO, ZnS, ZnSe, ZnTe, CdO, CdS, CdSe, CdTe, MgO, MgS, MgSe, MgTe, HgO, HgS, HgSe, HgTe, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InS, InN, InP, InAs, InSb, TlN, TlP, TlAs, TlSb, and mixtures thereof.

3. The system of claim 1 , further comprising a memory coupled to the processor, wherein the received color information includes at least one of hue, saturation, and intensity of the reflected radiation, and wherein the memory stores a table relating at least one of hue, saturation, and intensity of the reflected radiation to thickness of the thin-film material.

4. The system of claim 1 , wherein the processor includes analysis software to calculate the thickness of the deposited thin-film material.

5. The system of claim 1 , wherein a beam size of the optical radiation is about 1μm in diameter to about 100 mm in diameter.

6. The system of claim 1 , wherein a beam divergence of the optical radiation is about 0.001 NA to about 0.5 NA.

7. The system of claim 1 , wherein the optical radiation is a continuous wave.

8. The system of claim 1 , wherein the optical radiation is pulsed light.

9. The system as in claim 1 , wherein the atomic layer deposition apparatus is coupled to the processor and is controlled by the processor in accordance with the calculated thickness of the deposited thin-film material.

10. The system as in claim 3 , wherein the color information comprises hue information.

11. A method of controlling the deposition of a semiconductor material on a photovoltaic module substrate, the method comprising the steps of:

forming a conductive material over a photovoltaic module substrate;

depositing semiconductor material over the conductive material by an atomic layer deposition comprising a plurality of atomic layer deposition cycles;

illuminating a portion of the deposited semiconductor material with optical radiation;

using a colorimeter to detect color information related to reflected radiation from the deposited semiconductor material; and

calculating a thickness of the deposited semiconductor material based on the detected color information;

comparing the calculated thickness to a predetermined thickness; and

controlling whether additional semiconductor material is deposited by the atomic layer deposition based on the result of the comparison;

wherein the step of comparing the calculated thickness to the predetermined thickness occurs after every N deposition cycles executed during deposition of the semiconductor material, wherein N is a predetermined number.

12. The method of claim 11 , further comprising the step of outputting a stop signal to a deposition apparatus that is depositing the semiconductor material if the calculated thickness is equal to or greater than the predetermined thickness.

13. The method of claim 11 , further comprising the step of outputting a continue signal to a deposition apparatus that is depositing the semiconductor material if the calculated thickness is less than the predetermined thickness.

14. The method of claim 11 , wherein the value for N is reduced if a difference between the calculated thickness and the predetermined thickness is less than a predetermined value.

15. The method of claim 11 , wherein N has an initial value of between 1 and 50.

16. The method of claim 11 , wherein the semiconductor material is selected from the group consisting of ZnO, ZnS, ZnSe, ZnTe, CdO, CdS, CdSe, CdTe, MgO, MgS, MgSe, MgTe, HgO, HgS, HgSe, HgTe, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InS, InN, InP, InAs, InSb, TlN, TlP, TlAs, TlSb, and mixtures thereof.

17. The method of claim 11 , wherein the step of calculating the thickness includes using a table stored in a memory of a processor to relate the detected color information, including at least one of hue, saturation, and intensity, to thickness of the semiconductor material.

18. The method of claim 11 , wherein the step of calculating the thickness includes using analysis software to calculate the thickness of the deposited semiconductor,

wherein the analysis software calculates the thickness by:

determining wavelengths of peak color based on the detected color information, the wavelengths of peak color being the wavelengths of maximum emission, and

determining the thickness of the semiconductor material based on a known relationship between the wavelengths of peak color and material thickness.

Assignments (6)